The youngest of four children, Cecilia Muñoz was born in Detroit, Michigan on July 27, 1962, to parents who had immigrated to the United States from La Paz, Bolivia. In 1984 Muñoz graduated from the University of Michigan (Ann Arbor) with degrees in English and Latin Studies, and she subsequently earned a master's degree at UC Berkeley. She then took a job with the Roman Catholic Archdiocese of Chicago as head of the Legalization Outreach Program for Catholic Charities. Following the 1986 enactment of the Immigration Reform and Control Act—an amnesty program that allowed some 2.7 million illegal immigrants to receive lawful permanent residence (green cards) in the late 1980s and early 1990s—Muñoz operated twelve field offices throughout metropolitan Chicago and helped more than 5,000 immigrants obtain U.S. citizenship.

In 1996 Muñoz strongly opposed the welfare reform bill that would ultimately lift millions of welfare recipients out of poverty by moving them into paying jobs where they were able to earn their own way instead of being the wards of American taxpayers. Muñoz's chief complaint was that the bill made illegal immigrants ineligible to continue receiving food stamps and Supplemental Security Income (SSI).

Under Muñoz, NCLR advised the Mexican government on how to lobby for amnesty on behalf of illegal aliens in the United States. In recognition of her efforts in this regard, Mexico's Institute for Mexicans Residing Abroad rewarded Muñoz with its Ohtli Prize for her service to that country.

In 2000 Muñoz won a MacArthur Fellowship for her work with NCLR. Upon receiving the award, Muñoz announced that she would use the $500,000 that came with it to help bankroll La Raza's initiatives.

In the aftermath of the 9/11 terrorist attacks, Muñoz stated that “there’s no relationship between immigration and terrorism.”

In 2007 Muñoz supported portions of that year's Comprehensive Immigration Reform Act, particularly a measure that would have created a clear path to citizenship for illegal immigrants; indeed she described opposition to this provision as a “wave of hate.” However, Muñoz and La Raza emphasized that they would not ultimately support any bill in its entirety unless it included "a path to citizenship for the current undocumented population; the creation of new legal channels for future immigrant workers; a reduction of family immigration backlogs; and the protection of civil rights and civil liberties."

During the 2008 U.S. presidential campaign, Muñoz served as one of Barack Obama's top advisers on immigration issues and Hispanic relations. In January 2009, President Obama appointed her as director of intergovernmental affairs.

Three years after that, President Obama appointed Muñoz as director of the Domestic Policy Council. In so doing, Obama signed a waiver exempting her from his campaign pledge which stated that no political appointees in the Obama administration would be “permitted to work on regulations or contracts directly and substantially related to their prior employer for two years.” Muñoz's appointment was cheered by government unions like the Service Employees International Union and left-wing activist groups like the Center for American Progress.

In 2013, Muñoz supervised the drafting of Senate Bill 744—titled the Border Security, Economic Opportunity, and Immigration Modernization Act—sweeping immigration-reform legislation which was passed by the U.S. Senate in June of that year. Designed to provide a path-to-citizenship for the millions of illegal immigrants residing in the United States, the bill also set a legal threshold of 10 phony passports before a fraudster could be prosecuted for buying, selling, or using counterfeit documents; permitted drunk drivers to qualify for citizenship if they had fewer than three DUI convictions; included a "chain migration" clause that would vastly increase the flow of immigrants to perhaps 35 million over the next decade; and created a three-year slush fund of almost $300 million—a sum slated to increase in subsequent years—which would go to left-wing immigrant-rights groups like the Mexican American Legal Defense & Educational Fund and the National Council of La Raza. For additional details about Senate Bill 744, click here.

By Muñoz's reckoning, America is a nation rife with white racism and bigotry. "The line between anti-immigrant and anti-Latino is pretty thin," she once toldThe Washington Post. "The day when my kids can walk down the street and be called American, that's the goal." On another occasion, Muñoz toldThe Detroit News: “It gets old. We're tired of being treated as if we don't belong here."

Fiercely opposed to those who call for stronger border protections and the deportation of illegal immigrants, Muñoz asserts that “undocumented workers” have added as much as $10 billion to the U.S. economy.